@HockeyDad 

Were there any power related issues recently, such as lightning storms or power outages?  If so was the router connected to a surge protector with an active surge protection circuit?  If so or if there wasn't any such issues with power we would suggest moving the router to a different outlet, to rule out any potential loss of power.  Once that is done if the issue still exist a RMA would likely be warranted.  At whcih point we would suggest sending an email to support.usa@tp-link.com with a link to this thread so that they know what troubleshooting was already preformed and can begin the validation process for an RMA approval.

@Carl 

Same series of events happened again early this morning after moving the router to a different outlet on a different surge protector.

I will send an email to support to inquire about an RMA.

Thank you

Hardware Version: ArcherC4000 v2.0
Software Version: 1.1.1 Build 20190827 rel.78773

2020-02-13 04:51:34 led-controller[1227]: <6> 288051 Start to run WAN1_ON
2020-02-13 04:51:34 led-controller[1227]: <6> 288051 Start to run WAN0_OFF
2020-02-13 04:51:33 led-controller[1227]: <6> 288051 Start to run LAN_ON
2020-02-13 04:50:52 traffic-stats[6216]: <6> 269001 Clear all stats because time changed
2019-08-27 00:00:27 upnp[8753]: <6> 217504 Service start
2019-08-27 00:00:27 upnp[8753]: <6> 217505 Service stop
2019-08-27 00:00:26 remote-management[8457]: <6> 282505 Service stop
2019-08-27 00:00:14 led-controller[1227]: <6> 288051 Start to run WAN1_ON
2019-08-27 00:00:14 led-controller[1227]: <6> 288051 Start to run WAN0_OFF
2019-08-27 00:00:14 led-controller[1227]: <6> 288051 Start to run LAN_ON
2019-08-27 00:00:14 nat[7395]: <6> 211021 IPSEC ALG enabled
2019-08-27 00:00:14 nat[7395]: <6> 211021 L2TP ALG enabled
2019-08-27 00:00:14 nat[7395]: <6> 211021 PPTP ALG enabled
2019-08-27 00:00:14 nat[7395]: <6> 211021 SIP ALG enabled
2019-08-27 00:00:14 nat[7395]: <6> 211021 RTSP ALG enabled
2019-08-27 00:00:14 nat[7395]: <6> 211021 H323 ALG enabled
2019-08-27 00:00:14 nat[7395]: <6> 211021 TFTP ALG enabled
2019-08-27 00:00:14 nat[7395]: <6> 211021 FTP ALG enabled
2019-08-27 00:00:13 led-controller[1227]: <6> 288051 Start to run WAN1_OFF
2019-08-27 00:00:13 led-controller[1227]: <6> 288051 Start to run WAN0_ON
2019-08-27 00:00:13 led-controller[1227]: <6> 288051 Start to run LAN_ON
2019-08-27 00:00:12 nat[7395]: <6> 211501 Initialization succeeded
2019-08-27 00:00:12 nat[7395]: <6> 211501 Initialization succeeded
2019-08-27 00:00:11 led-controller[1227]: <6> 288051 Start to run WAN1_OFF
2019-08-27 00:00:11 led-controller[1227]: <6> 288051 Start to run WAN0_ON
2019-08-27 00:00:11 led-controller[1227]: <6> 288051 Start to run LAN_OFF
2019-08-27 00:00:10 led-controller[1227]: <6> 288051 Start to run STATUS_ON
2019-08-27 00:00:08 led-controller[1227]: <6> 288051 Start to run NIGHT
2019-08-27 00:00:08 led-controller[1227]: <6> 288051 Start to run GENERAL
2019-08-27 00:00:08 led-controller[1227]: <6> 288051 Start to run WIFI5G_2_ON
2019-08-27 00:00:08 led-controller[1227]: <6> 288051 Start to run WIFI5G_ON
2019-08-27 00:00:08 led-controller[1227]: <6> 288051 Start to run WIFI2G_ON
2019-08-27 00:00:08 traffic-stats[6149]: <6> 269504 Service start
2019-08-27 00:00:07 factory-reset[5151]: <6> 284504 Service start
2019-08-27 00:00:07 access-control[5067]: <6> 239504 Service start
2019-08-27 00:00:07 access-control[5067]: <6> 239503 Function disabled
2019-08-27 00:00:06 nat[4717]: <7> 211001 Flush conntrack
2019-08-27 00:00:06 nat[4717]: <6> 211502 Function enabled
2019-08-27 00:00:06 nat[4717]: <5> 211051 Create NAT chain succeeded
2019-08-27 00:00:06 nat[4717]: <6> 211501 Initialization succeeded
2019-08-27 00:00:06 nat[4717]: <6> 211501 Initialization succeeded
2019-08-27 00:00:05 basic-security[4470]: <6> 219504 Service start
2019-08-27 00:00:05 basic-security[4470]: <5> 219606 Flush conntrack table succeeded
2019-08-27 00:00:05 firewall[2397]: <6> 209504 Service start
2019-08-27 00:00:03 imb[3097]: <6> 218507 Daemon connection succeeded
2019-08-27 00:00:03 imb[3097]: <6> 218012 ARP Binding disabled
2019-08-27 00:00:03 imb[3097]: <6> 218506 Config interface initialization succeeded
2019-08-27 00:00:03 imb[3097]: <6> 218501 Initialization succeeded
2019-08-27 00:00:02 upnp[2983]: <6> 217504 Service start
2019-08-27 00:00:02 upnp[2983]: <6> 217505 Service stop
2019-08-27 00:00:02 remote-management[2684]: <6> 282505 Service stop
1970-01-01 00:00:07 led-controller[1227]: <6> 288504 Service start

@HockeyDad 

I am in the same boat.  It's annoying.  I have multiple 2.4 Ghz devices dropping off the Wifi.  These devices are specifically Tp link HS110 smart plugs.  The green light on WiFi signal on these plugs are still solid green but they have dropped off the wifi.

This is happening for me as well - is there no way to debug this further?

@HockeyDad 

 I just registered to say that my 3 week old AC4000 has been rebooting itself every 3 to 4 days for the past 2 weeks. Reading this has me worried. The router always comes back up and acts like nothing happened. But when it reboots I hear it click and all my devices lose internet while the router reboots. And the front internet light turns orange. Since I have had it less than 30 days I will try and exchange it at Microcenter where I bought it. If the replacement does too it I'll request a refund and buy another brand.

  I made sure that automatic reboot is not selected. I have it plugged into a UPS and there are no issues with the UPS. The router is warm but in no way is it hot. Don't have a good feeling about this.

So TP-Link ended up RMA'ing my router and providng a repalcement refurbished unit.  Emailing the support as instructed here in this thread, with a link to this thread, still required me to go through more troubleshooting to finally get approval for an RMA.

Thus far, the replacement unit has been working as expected.

Good luck to the rest of you expieriencing similar problems.  I'll note this thread if I encounter future issues with the replacement.